1. Field of the Invention
The present invention relates to alumina-silica ceramic and producing method thereof, more particularly to alumina-silica ceramic for protecting high velocity projectile.
2. Description of the Background Art
For the development of a good armor material, it is very important to design the microstructure of an armor material according to protective mechanism. The schematic diagram, which illustrates behavior during the penetration of projectile into a ceramic block, is drawn in FIG. 1. A severe plastic deformation and self-eroding of projectile 10 were occurred simultaneously while projectile were penetrating into a ceramic block 20. Also, the crushed small ceramic particles (region A) moved in reverse of projectile""s moving direction as illustrated in FIG. 1. At the region B in FIG. 1, the crushed small ceramic particles moved to the center of projectile. These particles collided against projectile and then scattered to the outside. According to the above mechanism, the followings are must be considered to design the microstructure of armor materials; First, it has to have a large capability of attenuation against high velocity shock wave. Second, it has to attenuate high velocity tensile/shear wave and consolidate dynamic fracture strength. Finally, it has a capability to be crushed to small particles and then scattered to the outside with high velocity. In order to demolish the head of projectile, the material can endure high velocity and high pressure shock wave as long as possible.
It is therefore an object of the present invention to design the microstructure of ceramic and to produce the designed ceramic material.
In order to achieve the above-described object of the present invention, there is provided alumina-silica ceramic for protecting high velocity projectile comprising: 30-40 vol. % of sphere-shaped alumina and 10-65 vol. % of mullite whisker as hard phases, and 5-50 vol. % of glass phase surrounding the hard phases.
There is also provided a method of producing alumina-silica ceramic for protecting high velocity projectile, comprising the steps of: mixing and milling 17-58 wt. % of alumina, 20-27 wt % of quartz, 27-35 wt % of kaoline, 8-11 wt % of feldspar and 2-3 wt. % of talc to make a slurry; adding a deflocculant and a binder into the slurry; drying the mixed slurry to powders; pressing dried powders to form a green body; sintering the body in a furnace; and cooling the body in the furnace.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description.